1. Field of the Invention
This invention relates to a sheet feeding apparatus for feeding sheets one by one, and more particularly to a sheet feeding apparatus for use in an image forming apparatus such as a copier, a facsimile apparatus, a printer or a scanner.
2. Related Background Art
In an image forming apparatus such as a facsimile apparatus, a separation feed portion for sequentially feeding originals one by one to an image reading portion for reading images is of a construction in which the release of the pressure contact of a separation pad brought into pressure contact with a separation roller for feeding originals on a stocking plate and separating the originals is possible, and is designed such that the pressure contact of the separation pad is not released in the case of plural-sheets feeding in which a plurality of originals are set and fed one by one, and the pressure contact of the separation pad can be released in the case of one-sheet feeding in which an original is set and fed. The pressure contact of this separation pad and the release of the pressure contact are designed to be manually effected.
In the above-described example of the conventional art, however, there has been the problem that if the pressure contact of the separation pad is released when one-sheet feeding of original is effected, and if a plurality of originals are set and fed with this separation pad of which the pressure contact has been released forgotten to be returned to its pressure contact position, the plurality of originals are all conveyed at once. Also, there has been the possibility that at that time, an inconvenience such as the jam of the originals occurs to an original conveying system.
So, it is the object of the present invention to prevent the return of pressure-released separating means to its pressure contact position from being forgotten, and prevent the occurrence of an inconvenience such as bad conveyance.
The present invention has been made in view of the above-noted situation, and the typical construction of the present invention for achieving the above object is a sheet feeding apparatus having a stocking plate on which a plurality of sheets are stackable, separating means for separating the sheets stacked on the stocking plate one by one by a pair of pressure contact members, feeding means for feeding the sheets, and pressure releasing means for releasing the pressure contact of the pair of pressure contact members, and having returning means for acting on the pressure releasing means to thereby return the pair of pressure contact members to their pressure contact state after the feeding of a sheet has been terminated when the sheets are fed with the pair of pressure contact members released from their pressure by the pressure releasing means.
According to the above-described construction, forgetting to return the pressure contact members to their pressure contact position after one-sheet feeding effected in the pressure-released state of the separating means by the pressure releasing means has been terminated can be prevented, and an inconvenience such as the bad conveyance of sheets caused by the forgetting to return can be prevented, and the usability and quality of the apparatus are markedly improved.